Edward greppin



lUNTTnn STATES PATENT Trice,

' EDWARD GREPPIN, OF BASLE, SW'ITZERLAND, ASSIGNOR TO JEAN ROD.

GEIGY, OF SAME PLACE.

PROCESS FOR THE PRODUCTION OF BLUE COLORING-MATTER.

SPECIFICATION forming part of Letters Patent No. 368.716, dated August 23, 1857.

Application filed January 6, 1887. Serial No. 223,580. (Specimens) To all whmn it may concern.-

Be it known that I, EDWARD GREPPIN, doctor of philosophy, of Basie, Switzerland, have invented a certain new and useful Process for the Production of Blue (loloriug-lllatters, called Gentianiue, of which the following is a specification.

The said invention has for its object the production of blue coloring-matters by the oxidation of a mixture of paramido-diniethylaniline and paraphenylendiamine in the presence of sulphureted hydrogen in acid solution.

Instead of paraphenylendiamine, I can as well take paratoluylendiamine, (paradiamidotoluoh) and instead of paramido-dimethylaniline the derivations of diethylauiline, dimcthylaniline,dimethylorthotoluidine, methylethyl-orthotoluidine.

Herctofore an intended blue coloring-matter was obtained by heating two molecules of paraphenylendiamine with one molecule of sulphur leueo base of Lanths violet:

(diinethyl-parapl1enylendiamine.

O 6 i l fparaphengzlendiamine.)

NIL

My product is obtained by treating one molecule of paraphenylendiamine and one molecule of dimethyl-paraphenylendiamine with sulphureted hydrogen and an oxidizing substance. This new color is of unsymmetri- 40 cal structure, as is to be seen by the following formula:

H /OI-I3 o n N c n, N 4 HN s cn N s on o n/ NHL, i 1 c H NH leuco base color-base of my product. The reaction is represented by the formula:

. CH3 H N o. I b d S (paradiamidotoluoh) in the presence of sulphureted hydrogen in acid solution.

In testimony whereof I hereunto sign my name, in the presence of two subscribing witncsses, this 21st day of December, 1886.

EDlVARD GREPPIN.

\Nitnesses:

GEORGE GIFFORD, OHS. A. RICHTER. 

